ABAX Sensing Analyses Apple iPad Pro LiDAR

Ningbo ABAX Sensing Electronic Technology Co. (Flying Core Electronics Co. in Chinese) develops iToF, dToF, and automotive LiDAR sensors and also publishes nice articles on ToF technology. One of them analyses Apple iPad Pro LiDAR:

"On this generation of DTOF sensor, its global frame rate is 30fps, and each frame contains 8 sub-frames. According to the previous four groups of light-emitting points, each group of light-emitting points is responsible for two sub-frames. In each sub-frame, there are many pulses with a pulse width of about 2-3 ns. Each sub-frame contains about 80,000 pulses, and about 4.8 million pulses are generated per second.

The number and power of pulses selected by Sony are still very controversial here. For SPAD, the number of signal photons in each pulse is as large as possible to ensure that each pulse has a greater probability of being detected. Moreover, the greater the number of pulses, the memory consumed for storing the histogram and the bandwidth consumed for transmitting the histogram will increase proportionally. This also puts great pressure on the data storage and transmission inside the chip. According to estimates, a data transmission rate of more than 10Gbit/s is currently required to completely transmit all signals. Since Apple and Sony have chosen this way, they have considerable confidence in their own technology."